FlexBus
MCF52277 Reference Manual, Rev. 1
18-14
Freescale Semiconductor
Figure 18-7. Basic Read-Bus Cycle
18.4.5.2
Basic Write Bus Cycle
During a write cycle, the device sends data to memory or to a peripheral device.
shows the
write cycle flowchart.
Figure 18-8. Write-Cycle Flowchart
FB_CLK
FB_R/W
S0
S1
S2
DATA
FB_TS
FB_A[23:0]
ADDR[23:0]
FB_D[31:
X
]
ADDR[31:
X
]
FB_CS
n
, FB_OE,
FB_BE/BWE
n
FB_TA
S0
S3
1. Select the appropriate slave device.
Assert FB_TA (external termination).
3.
1. Negate FB_TA (external termination).
1. Decode address.
1. Set FB_R/W to write.
Assert FB_CS
n
.
2.
1.
(auto acknowledge/internal termination).
Sample FB_TA low.
2.
1. Start next cycle.
ColdFire device
System
Drive data.
3.
2. Place address on FB_D[23:0].
2. Latch data on FB_D[31:
X
].
3. Assert FB_TS.
1. Negate FB_TS.
FlexBus asserts internal FB_TA
Summary of Contents for MCF52277
Page 22: ...MCF52277 Reference Manual Rev 1 Freescale Semiconductor xxii...
Page 32: ...MCF52277 Reference Manual Rev 0 xxxii Freescale Semiconductor...
Page 60: ...Signal Descriptions MCF52277 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 128: ...Static RAM SRAM MCF52277 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 140: ...Clock Module MCF52277 Reference Manual Rev 1 7 12 Freescale Semiconductor...
Page 172: ...Chip Configuration Module CCM MCF52277 Reference Manual Rev 1 9 16 Freescale Semiconductor...
Page 180: ...Serial Boot Facility SBF MCF52277 Reference Manual Rev 1 10 8 Freescale Semiconductor...
Page 188: ...Reset Controller Module MCF52277 Reference Manual Rev 1 11 8 Freescale Semiconductor...
Page 210: ...Crossbar Switch XBS MCF52277 Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 542: ...FlexCAN MCF52277 Reference Manual Rev 1 23 32 Freescale Semiconductor...
Page 724: ...UART Modules MCF52277 Reference Manual Rev 1 30 34 Freescale Semiconductor...
Page 740: ...I2 C Interface MCF52277 Reference Manual Rev 1 31 16 Freescale Semiconductor...
Page 790: ...Debug Module MCF52277 Reference Manual Rev 1 32 50 Freescale Semiconductor...